The present invention relates to a computer-implemented method for simulating a polymer material including a polymer, a filler and a modifying agent for increasing the affinity of the polymer to the filler, and evaluating the affinity, more particularly to a combination of a modified polymer model and a filler model which is specifically defined by a flat surface fixed to a space in which the modified polymer model is disposed.
In general, a rubber compound used in a pneumatic tire contains reinforcing filler such as carbon black and silica. For example, if a silica-rich compound is used as a tread rubber of a pneumatic tire, an internal energy loss of the tread rubber is decreased and the tire performance, e.g. rolling resistance may be improved. Such silica-rich compound contains a modifying agent to increase the affinity of the base rubber or elastomer to the silica filler. If the affinity is low, the strength of the rubber compound is decreased with the increase in the content of the filler.
In recent years, on the other hand, in order to develop a rubber compound, the use of a computer simulation is proposed.
Japanese Patent Application Publication No. 2006-064658 discloses a computer-implemented method for evaluating a rubber material containing rubber and carbon black, and teaches to use a carbon model defined according to the molecular structure of the carbon black namely a graphite structure containing carbon atoms and a rubber model defined according to the molecular structure of the base rubber.
If such carbon models and rubber models are arranged dispersively, freely-movably in a virtual space, and a relaxation calculation is made based on molecular dynamics, then it takes much time to complete the relaxation calculation.